Specifications

DTT 7685x
SBU Technology – Tuners ATSC half NIM with Ch 3 / 4 modulator
20 Apr 2007
Preliminary Specification Page 14 / 29
IF AGC amplifier Enable (CD6)
IFE IF AGC Amplifier Function
0 Power down
1 Normal operation
Saw Drive output select (CD7)
SAS SAWF output Drive
0 Analogue output enabled
1 Digital output enabled
AGC setting control bits (CD6)
Wideband AGC Take Over Point setting (AT2, AT1, AT0)
IF Output Level @pin17
(dBuV@75Ω)
AT2 AT1 AT0
105 0 0 0
103 0 0 1
101 0 1 0
99 0 1 1
97 1 0 0
94 1 0 1
91 1 1 0
87 1 1 1
Default state in power up: 000
a) Recommend wideband AGC TOP setting “0 1 1” for digital reception
b) Recommend external conventional AGC for analog reception
AGC Function (CD7)
AGD Remarks
0 AGC enabled
1 AGC disabled
Wideband AGC Time Constant ATC (CD6)
ATC Remarks
0 IAGC = 10uA; (Time constant ≈ 100mS)
1 IAGC = 0.3uA; (Time constant ≈ 3S)